William b



(No Model.)

W. B. MANN.

DENTAL ENGINE HAND PIECE.

Patented Mar. 22, 1887.

E. man.

UNITED STATES PATENT @irrita VlL-LTAM BJMANN, OF BALTIMORE, MARYLAND.

DENTAL-ENGINE HAND-PlECE.

SPECIFICATION forming part of Letters Patent No. 359,798, dated March 22, 1887.

Application led October 28, 1886. Serial No. 217,408. (No model.)

.To @Z3 whom it 12mg/ concern:

Be it known that I, WILLIAM B. MANN, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful improvements in Dental-Engine Hand-Pieces, oi' which the following is a specification.

My invention .relates to hand-pieces for dentalengines, and has for its object to provide a superior hand-piece, one which in practice will meet all the requirements demanded .of such devices.

The invention will lirst be described inconnection with the accompanying drawings, and the subject-matter thereof will then be set forth in the claims.

The drawings illustrate the construction of the several features of my improvements.

Figure 1 is a longitudinal central section through a hand-piece embracing my improvements. Fig. 2 is a view of the spindle. Fig. 3 is a view of two grip-jaws and a t-ool in position to be gripped thereby. Fig. 4. is a crosssection of the two grip-jaws on the line l 4. Fig. 5 is a cross-section of the two grip-jaws on the line 5 5. Fig. 6 is a side View of a tool. Fig. 7 is a longitudinal section of the conipressor-slidc which opens the grip-jaws, on the plan shown in Fig. l. Fig. 8 shows the two parts of the screw-threaded collar for actuating the compressor-slide which opens the grip-jaws. Fig. 9 is a side view of the shank section of the case. Figs. 10 and l1 are longitudinal section and side views, respectively, of a portion of a hand-piece, and illustrate a niodilication of the spring and slide and collar by which the grip-jaws are actuated.

The tubular casing of the hand-piece is cornposed of two sections, the hand-section A and the shank-section B, which two parts are united by the screw-thread a.. The shank-section at one end has a screw-thread, b, for connection with the end of the usual flexible sheath which surrounds a flexible shaft used in dental engines. The spindle C of the hand-piece is designed to have its end b secured to the said Neither the sheath nor the flexible shaft. liexible-shaft are shown in the drawings, as they forni no part of rny present invention.

The nozzle end c of the hand-piece has on its inner side a roamed-out or tapered bearing,

cl, against which the cone-pointed tubular end d of the spindle C rests. die is tubular and receives the shank end of the tool D. The spindle C extends longitudinally through the hand-piece casing, and has bearings therein, as hereinafter described. The rear part, c, of the spindle is reduced, or smaller in size, and a tapered or cone-shaped shoulder, e', is turned at the point where the reduced part unites with the larger part. A movable bearing, E, occupies the shanksection of the case, and is centrally bored to 4permit the reduced part e of the spindle to pass through it. This bearing is adapted to slide longitudinally in the oase B, and its front end bears against the said cone-shaped shoulder e' and serves to keep the cone-pointed end d of the spindle snugly or properly in contact with the roamed-out bearing d at the nozzle end. lt will thus be seen v that all lost motion or looseness of the spindle that may be occasioned by wear may be readily taken up by adjusting the movable bearing E. This adjustment may be effected by any convenient device. ln the present instance the shank-section B has a longitudinal slot-,J2 and a screw, g, set in the movable bearing E, projects through the said slot. By tightening the screw g its head will bind on the outside of the oase B, and retain the bearing E wherever set. lVhen the screw is loosened, the bearing E may be adjusted.

Two pivot-ed jaws, F, are employed to grip the shank end of the tool D. The sbanlrs k of these jaws are bot-h pivoted to the spindle C at a point, h, back of its tubular end, where the spindle has a slot, i, (see Fig. 2,) which is occupied by the two jaws F when they are gripping the tool-shank. This will be understood by reference to Figs. 1 and 2. lVhen thus gripped, the tool-shank occupies the tubular end d of the spindle, and the jaws which grip it are closed together in the slot@l of the spindle, and thereby are prevented from lateral movementor slipping, and consequently they hold the tool with great firmness.

The slot i in the spindle need not extend the length shownin the drawings. It would be sufiicient it'vthe slot were adjacent to the tubular end and long enough only to admit the jaws F when closed together.

Means to close the grip-jaws and means to This end ofthe spin- Y IOO open them are employed. Two plans to this end are shown. The. rear ends of the jawshanks k extend back from the point h, and a spring, Z, (see Figs. 1 and 2,) secured to the spindle @,presses against the said jaw-Shanks, and by spreading them apart serves normally to close the jaws F on the tool-shank. A sliding compressor, G, (see Figs. l and 7,) occupies the case,and has a center hore,m, through which the spindle C passes. This compressor therefore serves as a bearing to steady the rotating spindle. The front end of the compressor has a bell-shaped socket, n, and the` extremities of the jaw-Shanks k are in position to enter this socket, which they do when the compressor G is crowded forward. When this forward movement of the compressor takes place, the result is to compress the two jawshanks 7c together, and thereby open thejaws F and release the tool. By providing the two pivoted jaws with rear end shanks extending back from the pivot, a very slight movement of the compressor G will operate the jaws.

The sliding compressor G is moved forward and back by the exterior screw-thread collar i H H. (See Fig. l.) This collar is made in two parts, which are shown together in Fig. l and separate in Fig. 8. One part, H, has an internal screw-thread, o,which takes on an external screw-thread on the case A,and also has an exterior `knurl or rough surface, p, by which it may be grasped. The other part, H', of the collar has an internal annular groove, Q, which receives the head of two or more screws, r, which are set in the sliding compressor G. Each of these screws project outward through a longitudinal slot, s, in the case A. Instead of the screws r, pins may be used. The two parts, H and H, of the collarA are coupled together by any suitable means-An the present instance by a screw-connection, t. From this description it will be understood that by grasping the rough surface of the collar H and turning it, it will be moved according to the direction in which itis turned, either forward or back, on the case A, and the compressor Gwithin the case will be made to slide in like manner. It will thus be understood that Fig. l illustrates one plan or one construction of parts for actuating the grip-` jaws F. In this plan the spring Zcloses the jaws and the slide G opens them. Another plan for effecting this end is shown in Figsl() and l1, and is the equivalent of the one just described. Here the action of the partsis reversed. The spring Z opens thejaws and the slide G closes them. In this plan the slide G has a center bore for the passage of the spindle, and an external annular groove, q'. The front end of the slide has a rounded protuberance or cone-point,- a', and the extremities of the jaw-Shanks 7c are in position to be spread apart `by said cone-point when the slide is crowded forward, and when this forward movement takes place thejawsF will be closed. The slide G is moved forward and back by the following means: An exterior collar, H2, has two pins, r, each of which projects inward through a spiral slot, s', in the case A and into the annular groove q on the slide. By partly turning the collar H2 one way or the other, the

slide G will be moved, as desired, either forward or back. A spring, a, around the spindle keeps the slide G pressed forward. The

pivoted grip-jaws F, attached to a spindle, in i shown at n, is halved.: The outer side, o', is

rounded, and the inner side, o2, is flat. The end also has a notch, w. The shape of the jaws corresponds to that of the shank end n.

In the grip-face of each jaw'is a groove, x, and` one of them has in its groove a lug, w', to enter the-notch in the shank end. This construction of the grip-jaws prevents the tool from,

turning or drawing ou t.

The two pivoted grip-jaws here shown and the coacting parts differ in their shape, construction, and manner of operating'fromthe` two `flat spring tool-locking devices heretofore used, and also from the single tool-locking latch pivoted Inidwayof its two endsheretofo're used.

Having described my invention, I claim and desire to secure by Letters Patent of the United Statcs l. The combination of the tubular casing provided with a nozzle end, a spindle extending longitudinally through and tunning in bea-rings in the tubular casing, two grip-jaws piv-` oted to the spindle and each jaw having a rear end shank extending back from the pivot, and means, substantially as described,` acting on the said rear end shanks to operate the jaws, for the purpose set forth.

2. The combination of the tubular casing provided with a nozzle end, a spindle extending longitudinally through and turning in bearf ings in the tubular casing, two grip-jaws pivoted to the spindle, each jaw having in its face a longitudinal groove, one side of which lis partly rounded and the `other flat, whereby the tool is prevented from turning,and one jaw having a cross-lng,w,in its groove, whereby the tool is prevented from drawing out, as set forth;

IOO

In testimony whereof Iaffix my signature in thepresence of two witnesses,

wir'. Banaan.

lN-Titnesses:

JOHN E. MORRIS, ,-f JNO. T. MAnDox. 

